Automotive vehicle automatic temperature control system

ABSTRACT

Automatic temperature control system for the passenger compartment of an automotive vehicle. The control is by vacuum modulated by the temperature of ambient air and the temperature of air in the passenger compartment of the vehicle and includes a vacuum motor operated by modulated vacuum regulating the position of a plenum mounted air blend door, controlling the passage of cold, tempered or heated air into the passenger compartment and positioning an electrical programmer, to provide the desired blower speeds and certain program functions of the system.

United States Patent [1 1 Franz Nov. 27, 1973 Primary Examiner-CharlesSukalo Attorney-Carlton Hill et al.

Rudolph J. Franz, Schaumburg, Ill.

[75] Inventor: [73] Assignee: Eaton Corporation, Cleveland, Ohio [57]ABSTRACT [22] Filed: Malia 28 1972 7 Automatic temperature controlsystem for the passenger compartment of an automotive vehicle. The conlPP 238,838 trol is by vacuum modulated by the temperature of a ambientair and the temperature of air in the passen- 52 US. Cl. 165/23 165/42mPaflmem 0f the vehicle and includes a [51] Int. Cl Bflh 3/04 I motoroperawd by modulated vacuum regulating 58 Field of Search 165/23 41-44the 1 a Plenum mum! air blend trolling the passage of cold, tempered orheated air [56] References Cited into the passenger compartment andpositioning an electrical programmer, to provide the desired blowerUNITED STATES PATENTS. speeds and certain program functions of thesystem. 3,315,730 4/1967 Weaver et al 165/23 18 Claims, 5 DrawingFigures 9 CAR /9 Z 22 m1. ems/v0 Dank SERl/d ilk Run?

EC/Ra PATENTEU NOV 2 7 I973 SHEET 30F 3 AUTOMOTIVE VEHICLE AUTOMATICTEMPERATURE CONTROL SYSTEM FIELD OF THE INVENTION Automatic temperaturecontrol for the passenger compartment of an automotive vehicle of thetype coming under Classes 165 and 237.

BACKGROUND, SUMMARY AND ADVANTAGES OF INVENTION This invention is animprovement in the automotive temperature control systems disclosed inthe U.S. Pat. No. to Freiberger 3,433, 130; Templin et al. 3,460,754 andGaskill et al. 3,263,739 in the simplification and efficiency of thecontrol by the provision of a vacuum operated servo motor operated bymodified in-car and ambient temperatures and connected to operate theair blend door of the system directing the air, which has previouslypassed through the evaporator coil, to either flow through the heatercore for reheating or to bypass the heater core for proper airdistribution or to flow solely through the heater core. The electricalprogrammer for the system is positioned by the vacuum motor inaccordance with ambient and in-car temperature conditions and theposition of the air blend door, and positively shuts off the hot watervalve where maximum air conditioning is required, and has anelectro-vacuum relay energized through the programmer and operable tokeep the outside air door closed and the blower off, when the engine iscold and until a preselected temperature of the engine is attained, aswell as to keep the outside air door closed when maximum heating isrequired.

The system further provides a low blow purge effective to purge theplenum of stale air as the fresh air door is closed and therecirculation door opens to recirculate heated air through the passengercompartment. The control of the electrical and pneumatic componentscontrolled by the programmer has provisions for overriding either thepneumatic or electrical circuitry where full circulation of air andchanges in the sequence of operation of the various air circulationducts are required.

An advantage of the invention is the simplification of the system andmore positive and selective control in accordance with temperatureconditions, by the provision of a servo motor operated by vacuummodulated in accordance with in-car and ambient temperatures andoperating an electrical programmer forming a part thereof, carrying outthe program of operation of the system in accordance with thetemperature conditions and shutting off the hot water valve upon extremehigh temperature conditions, as the air blend door reaches the end ofits travel to provide conditioned air to the system upon overtravel ofthe servo motor relative to the air blend door.

A further advantage of the invention is the deenergization'of the blowermotor when the engine is cold and heat is required until the enginetemperature reaches a preselected value and the holding of the airrecirculation duct closed, to prevent cold fresh air from entering thepassenger compartment of the automotive vehicle until the temperature ofthe coolant rises to the extent required to heat the air to acomfortable temperature, together with a low speed blower purgeeffective to purge the plenum of stale air prior to cycling of theblower at its required blower speeds.

Another advantage of the invention is that the heat ing and cooling ofthe vehicle may be automatically controlled by vacuum modulated inaccordance with in-car and ambient temperatures, and the program forheating and cooling is in accordance with the position of the air blenddoor of the air conditioning system.

A further advantage of the invention is in the simplicity and efficiencyof the system and the provision for manually overriding the programmingof the blower motor and the pneumatic and electric circuitry at theselection of the operator.

Other objects, features and advantages of the invention will be morereadily apparent from the following description of a preferredembodiment thereof, taken in conjunction with the accompanying drawings.although variations and modifications may be effected without departingfrom the spirit and scope of the novel concepts of the disclosure.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view illustrating thevacuum controls and motors for an automotive heating and cooling systemconstructed in accordance with the principles of the present invention.

FIG. 2 is a diagrammatic view illustrating the electrical programmer andcontrols for the system cooperating with the vacuum controls.

FIG. 3 is a partial fragmentary longitudinal sectional view takenthrough the power servo and programmer of the present invention.

FIG. 4 is a top plan view of the programmer shown in FIG. 1 with thecontact plate removed; and

FIG. 5 is a fragmentary transverse sectional view taken through the formof electro-vacuum relay utilized in the present invention with certainparts removed and certain other parts broken away.

DESCRIPTION OF A PREFERRED EMBODIMENT OF INVENTION In FIG. 1 of thedrawings, the vacuum components of an automatic temperature controlsystem are shown in diagrammatic form as including a temperature sensorand vacuum modulating valve 10 of a type shown and described in my U.S.Pat. application Ser. No. 71,765, filed on Sept. 14, 1970 and entitledTemperature Control System and Vacuum Modulator Valve Therefor shown assupplying modulated vacuum to a vacuum servo motor 11 and to a vacuumselector 12, which may be a rotary selector of a type wellknown to thoseskilled in the art so not herein shown or described in detail. Thevacuum motor 11 has a plunger 13 extending therefrom having connectionwith an air blend door 15 through a tension spring 16 serving as anovertravel spring accommodating retractable movement of the plungerrelative to the air blend door, when the air blend door is in a maximumair conditioning position.

A blower 17 driven by a blower motor 18 is provided to blow airat'ambient temperature through a duct 19 of the sensor and vacuummodulating valve 10 along an ambient bimetal element 20. The ambient airduct 19 terminates into a reduced cross-sectional area discharge end,and draws air through an in-car duct 21 along an in-car bimetal element22. The ambient bimetal element 20 and in-car bimetal element 22 areconnected to operate a vacuum control valve 23 modulating vacuum inaccordance with incar and'ambient temperature requirements. The vacuummodulator valve 23 has a vacuum output 24 connected with manifold orsource vacuum, which draws vacuum modulated in accordance withtemperature conditions into the valve through a vacuum input 25connected with a vacuum output 26 of the vacuum motor 11, in the mannershown and described in my prior application Serial No.

The vacuum output 24 is connected with a vacuum storage tank 27 througha vacuum line 28. Said storage tank is connected with engine vacuum, asfor example, the intake manifold of an internal combustion engine (notshown) through a connector fitting 29 which may be threaded within orotherwise connected in the manifold. A vacuum output 30 of the selector12 is connected with the vacuum line 28 and connects ports 7, 8 and 9 ofsaid selector to vacuum. A vacuum output 31 of an electro-vacuum relay32 is also connected with source vacuum through a vacuum line 33.

A vacuum operated water valve solenoid 35 has a vacuum output 36connected with source vacuum through a vacuum line 37.

When the vacuum selector 12 is in an automatic position, a port 4 of thevacuum selector connected with modulated vacuum has connection with aport 2 of the selector which is connected with a vacuum output 39 of aservo vacuum motor 40 through a vacuum line 41. The servo vacuum motor40 has a plunger 42 extending therefrom and retractable with respect tosaid motor upon predetermined increases in vacuum, and connected at itsouter end to a mode door 44. Said mode door 44 controls the circulationof the air and smoothly distributes air smoothly simultaneously from theinstrument panel and floor registers during a transition from heat toair conditioning mode and vice versa and positions the door todistribute air through the panel during cooling by the air conditionerand through the floor during heating.

The electro-vacuum relay 32 has a vacuum input 45 having a restriction46 therein connected. A vacuum line 47 connects said vacuum input 45with a port 3 of the selector 12. Said electro-vacuum relay is shown inFIG. 5 and will hereinafter be more fully described as thisspecification proceeds.

When the selector 12 is in its automatic position, the port 3 hascommunication with the port 1 having communication with the vacuumoutputs 48 and 49 of vacuum motors 50 and 51, respectively, through avacuum line 52 and a branch vacuum line 53. The vacuum motor 51 has aplunger or operator 55 connected with a recirculation door 56 for movingsaid door from an open to closed position upon retractable movement ofthe plunger 55, to effect the recirculation of either heated or cooledair through the passenger compartment of the vehicle, for maximumheatingand cooling conditions. The vacuum motor 50 has a plunger oroperator 57 retractable therein upon the connection of the vacuum output48 to source vacuum through the electrovacuum relay 32, for opening afresh air door 59 asthe recirculation door 56 is closed to accommodatethe circulation of fresh air through the passenger compartment duringheating, cooling or venting of the passenger compartment. Theelectro-vacuum relay 32 is adapted to keep the fresh air door closed andthe system off until a specific coolant temperature is attained, as wellas to keep the fresh air door closed when maximum cooling is requiredunder control of the programming circuit as will hereinafter moreclearly appear as this specification proceeds.

The water valve solenoid 35 and valve controlled thereby are under thecontrol of the electrical programming circuit and may be a conventionalform of solenoid and valve open upon deenergization of the solenoid, soneed not herein be shown or described in detail. The valve of the vacuumwater valve solenoid 35 has connection with a water valve vacuum motor60 through a vacuum line 61. The vacuum motor 60 has a plunger 62,retractable with respect to said motor upon the connection of said motorto source vacuum through the water valve and a vacuum line 37. Theplunger 62 is diagrammatically shown as having operative connection witha water valve 63. The water valve 63 may be of any conventional form andis in its wide open position upon deenergization of the water valvesolenoid. The plunger 62 is biased to close said water valve uponenergization of said solenoid under the control of the servo programmer(FIG. 2) actuated by the servo motor 11.

A defrost or defog vacuum motor 66 has a vacuum output 67 connected withthe selector 12 through a vacuum line 69 connected with a port 5 of saidselector. The defrost vacuum motor may be of a type having dualdiaphragms, in which one diaphragm retractable moves a plunger 70 ofsaid vacuum motor a predetermined distance to move an air circulationdoor 71 operated by said plunger one half of its travel upon setting ofthe vacuum selector in a defog position, to connect the vacuum line 69to source vacuum. The vacuum motor 66 also has a second vacuum output 72connected with a port 6 of the selector 12 through a vacuum line 73 andthereby moving the door 71 to its full defrost or deice position to senda maximum amount of hot air over the windshield and windows whereprovision may be made by appropriate ducts to defrost the side windowsas well as the rear window.

Referring now in particular to FIGS. 2, 3, 4 and 5, and the programmingcircuit providing the desired automatic blower speeds together with thenecessary program functions, the servo motor 11 has an electricalprogrammer as a part thereof and operated in accordance with modulatedvacuum in the chamber for the motor. The programmer is shown in FIGS. 3and 4 as a sliding type of switch having a series of sliding contactfingers 74,75, 77,78 and 79 movable along stationary contacts80,81,82,83,84 and 85, respectively, diagrammatically shown in FIG. 2 asextending along a stationary contact plate 86. The contact plate 86forms a top cover for a programmer housing 88 and is suitably securedthereto (FIG. 3). The stationary contacts 80 to face downwardly and areslidably engaged by the sliding contact fingers 74,75 and 77,78 and 79,carried on an insulated slide plate 89, slidably guided in theprogrammer housing 88 to cut resistors into and out of the circuit tothe blower motor 18 and to thereby operate said blower motor at its 4automatic blower speeds and also to control certain programmedoperations of the system.

The programmer housing 88 is mounted on a plate 90, which may be a metalplate and is mounted on a casing part 91 of the servo motor, between apair of upright arms 92, which may be formed integrally with said plate.The programmer housing in turn is provided with aligned laterallyextending ears 93 having slots 94 therein, through which machine screws95 pass. The

machine screws 95 may be threaded in the plate 90 and afford a means foradjusting the position of the contact plate 86 relative to the contactfingers 74,75 and 77,78 and 79, to vary the timing of the programmingoperation and to thereby enable the contact plate 86 to be positioned tocarry out the control functions at the proper time.

The bottom of the programmer housing 88 has a slot 96 extendingtherealong registering with a slot 97 formed in the plate 90, andreceiving a slotted drive ear casing part 91. Said U-shaped lower endportion has an inwardly extending leg 104 riveted or otherwise securedto a horizontal leg 105 of an angle 106 and accommodates movement of thearm 102 along the easing part 91. The vertical leg of the angle 106extends downwardly along the outside of a diaphragm 107 to and beneaththe center thereof along the outside of a diaphragm plate 108 extendingalong the outside of said diaphragm. An internal diaphragm reinforcement109 of a generally cup-like form, abuts the inner end and sides of thediaphragm when the plunger 13 is in its extended position. The verticalleg of the angle 106 may be formed integrally with the plunger 13 and isriveted to the plate 108 and the base of the cup-like diaphragmreinforcement 109 by a rivet 110. The end wall and top portion of thecylindrical wall portion of the casing part 91 are slotted toaccommodate the horizontal leg 105 to extend from said casing part andto accommodate full retractable movement of the diaphragm 107 and theplunger 13.

The casing part 91 is abutted by a casing part 11 1 and has an outwardextending radial flange having a sealing groove 112 extendingthereabout, and affording a means for sealing the diaphragm to thecasing parts 91 and 111. The casing part 111 has a radial flangedportion 113 crimped about the radial flange of the casing part 91 in aconventional manner. A compression spring 115 is provided to bias thediaphragm 107 and plunger 13 in the extended position shown in FIG. 3.

The stationary contacts 80 on the contact plate 86 comprise a series ofspaced contacts successively engaged by the contact finger 74 as thepower servo motor is operated by vacuum modulated by the ambient andin-car temperature sensitive elements and 22, respectively. In FIG. 2 ofthe drawings the contact fingers 74,75 and 77,78 and 79 may move fromthe left to the right hand side of the contact plate 86 during the heatmode, to first energize the blower at a high blower speed andsuccessively reduce the blower speed to its fourth or lowest speed asthe contact finger engages the center contact of the contacts 80. Thefirst contact 80 on the left hand side of the contact plate 86establishes a direct energizing circuit to the blower motor 18 throughcontacts R and M of a blower switch 116, a conductor 117, a contact 118and switch arm 119 of a high speed blower relay 120 and a conductor 121leading from the switch arm 119 to the blower motor 18.

This provides the high blower speed required to warm up the passengercompartment of the vehicle.

It should here be understood that the contacts R and M are electricallyconnected by sliding contacts 155. These contacts include contacts 155electrically connected together and two other contacts 155h electricallyconnected together and insulated from the contacts 155. As the contactfinger 74 moves to the right, the successive contacts engaged therebywill cut resistance 3R, 2R and IR into the blower motor circuit.

The contact 81 is energized through a delay switch 151, an electrovacuumrelay switch 140 and a contact A of a selector 122 connected to battery124 through an ignition switch 123 and conductor 125. A fuse 126 isshown as being in the conductor 125. The contact 81 is energized duringthe heating cycle only.

When the temperature of the passenger compartment rises to the extentthat air conditioning is required, the slide 89 will have moved alongthe programmer housing 88 to engage the contact finger 74 with thecontact 80 connected with the blower motor 18 through the threeresistors 1R,2R and 3R. Current will be supplied to the contact finger74 through the contact finger 76 engaging the contact 82. Said contact82 controls the blower speeds during the cooling cycle. As

the temperature within the vehicle increases with a correspondingincrease in ambient temperature, the contact finger 74 will cut out theresistors 1R,2R and 3R from the blower motor circuit and increase theblower speed to a high blower speed, with all of the resistance cut outof the motor circuit as the contact finger 74 contacts the next to thelast contact 80. The last contact is provided to energize the blowermotor at high blower speed upon overtravel of the servo motor 11. Thecontact 82 is energized through contact A of the selector switch 122through a conductor 127. When the contact finger 74 engages the next tothe last contact 80, the air blend door 15 will be in its maximum airconditioning position. As the temperature increases, however, overtravelof the diaphragm 107 and plunger 13 will take place against the tensionspring 16. The contact finger 74 will then engage the last contact 80 onthe contact plate. An energizing circuit is complete to the blower motor18 through a conductor 129 connected with a contact H of the blowerswitch. The contact H has energizing connection with a contact 130through the slide contacts 155h. The contact 130 is connected with acontact 131 of the blower switch through a conductor 132. The contact131 in turn is connected with a relay coil'133 of the high blow relay120 through a conductor 134. This will energize said relay coil andengage the switch arm 1 19 with a contact 135 of said relay. The blowermotor will then be directly connected with the battery 124 through aconductor 136 and the blower will be driven at a high blower speed whenmaximum cooling is required.

In this position of the contact fingers 74 and 75, the contact finger 77will engage a contact 83. This will complete an energizing circuit to asolenoid coil 137 for the water valve solenoid 35, and open the watervalve (not shown) of said water valve solenoid and connect the servomotor 60 to source vacuum. This will effect movement of the water valve71 to a closed position and hold the valve in such a position. The flowof water to the heater coil (notshown) will thus be shut off whenmaximum cooling is required. As the contact finger 77 engages thecontact 83, a contact finger 79 electrically connected with the contactfingers 77 and 78 will engage the contact 85 and energize a solenoidcoil 139 of the electro-vacuum relay 32 and open contacts 140 of therelay switch 141. Energization of the solenoid coil 139 will also open avalve 145 of the relay 32, and effect the connection of the servo motors50 and 51 to the source of vacuum to close the fresh air door 59 andopen the recirculating door 56 to recirculate cooled air through thepassenger compartment of the vehicle.

The electro-vacuum relay 32 as shown in FIG. is of a type operating onprinciples somewhat similar to the valve shown and described in anapplication US. Pat. Ser. No. 195,239 filed by Rudolph J. Franz, John S.Freismuth and Lena Benedetti on Nov. 3, 1971 and entitled EmissionsReduction Vacuum Control Valve," so need only be generally referred toherein.

As shown in FIGS. 1 and 5, the vacuum output 31 is connected with sourcevacuum through the vacuum line 33. Said vacuum output 31 has a valveseat 144 forming a seat for a resilient ball-type valve 145. The valve145 is carried at the center of an armature plate 146. A conical spring147 engages said armature plate and biases the valve 145 in a closedposition. Energization of the solenoid coil 139 moves the armature plate146 and valve 145 in a direction to open said valve. Source vacuum willthen draw vacuum through the vacuum input 45 through a restriction 46 insaid vacuum input and out through the vacuum output 31. This willconnect the motors 50 and 51 to source vacuum through the selector 12and close the fresh air door 59 and open the recirculating door torecirculate cooled air through the vehicle.

The ball valve 145 is engaged by a plunger 148, which in turn engages amovable contact 141 on the switch arm 140 to open the circuit throughthe relay as the solenoid coil 139 is energized. The switch arm 140 isbiased to close a circuit to the blower motor 18 upon deenergization ofthe solenoid coil 139, at which time the valve 145 will close and blockthe flow of vacuum into the valve through the vacuum input 45 and outthrough the vacuum output 31.

The solenoid coil 139 of the electro-vacuum relay 32 is energizedthrough a conductor 149 connected with ground through a thermallyresponsive engine switch 150. The engine switch 150 may be a bimetallictemperature sensing switch, which is closed when cold and opens todeenergizing the solenoid coil 139 when the engine coolant reaches acomfortable circulating temperature, as between 120 to 140 F.

As the switch 150 is closed, the solenoid coil 139 will be energized toopen the valve 145 and connect the fresh air vacuum motor and therecirculating vacuum motor 51 to source vacuum through the vacuum intput45 and the bleed passageway or restriction 46. This will delay openingof the recirculating door and thereby prevent cold air from entering thepassenger compartment. This delay is dependent on engine size and willtake anywhere from 1 to 5 minutes. Energization of the solenoid coil 139will move the contact arm 140 to break the circuit to the blower motor18, and thereby keep cold air from being blown into the passengercompartment until the engine warms up.

Referring now to the low blow purge of the system, the recirculatingservo motor 51 is shown in FIG. 1 as having the delay switch 151 carriedthereon. Said delay switch 151 may be a form of limit switch actuated bya plunger 151a biased into engagement with the diaphragm (not shown) ofthe servo motor 51. Said plunger 151a closes said switch to establish anenergizing circuit to the contact 81 after the relay switch 140 hasclosed, in a manner well known to those skilled in the art, so not shownor described in detail herein.

The delay switch 151 closes in a predetermined time delay of between tenand fifteen seconds after closing of the contacts of the relay switch140. Thus, as the engine warms up and the temperature sensitive switch150 opens, the delay switch 151 will be open. The blower motor 18 willthen be energized through the relay switch 140, a conductor 152 and theresistors 1R,2R and 3R. This will effect a low blow purge of the plenumof stored air prior to operating the blower at its high blower speed,through contact 81, contact fingers and 74 and the first stationarycontact at the left hand side of FIG. 2, as previously described.

The system also includes an ambient thermally responsive switch 153 inthe circuit to a solenoid coil 154 when said selector is in itsautomatic or deice position, energized through the selector 122 toeffect engagement of the compressor clutch whenever the ambienttemperature is above a predetermined low temperature, which may be inthe order of 40. An override for the ambient switch 153 (not shown) maybe provided where it may be desired to override the ambient switch aboveor below the temperatre of closing of the temperature sensitive ambientswitch 153.

The sliding contacts 155 movable along the blower switch 116 arenormally in position to complete a circuit through contacts R and M. Thecontacts 155 and 155h may also be manually moved along said blowerswitch to complete a circuit between the contact B of the blower switchand a contact 156, connecting the blower in the circuit through aconductor 157 and resistors SR and 6R. The contacts 155 may also bemoved to complete a circuit between the contact B and a contact 159 andeffect energization of the blower motor 18 at a higher speed through theresistor 6R. Further movement of the sliding contacts may also completea circuit between the contact B and the contact 131 and energize thesolenoid coil 133 and complete a circuit between the contact 135 andcontact arm 119 and the conductor 136 connected to the battery 124through the conductor 123. The blower switch 116 thus provides threemanually controlled blower speeds to override the four programmedautomatic blower speeds.

When the system is to be automatically controlled the selectors 12 and122 may be set in an automatic position. 1f the ambient temperature isbelow 40 the ambient switch 153 will be open and the compression clutchwill be deenergized. If the engine coolant is cold, the temperaturesensitive engine switch 150 will be closed. The solenoid coil 139 willthen be energized and the swtich arm 140 will move to its open position.This will open the valve and connect the servo motors 50 and 51 to asource of vacuum through the selector 12 and the bleed orifice 46. Theblower circuit will then be broken and the recirculating door will bekept in a recirculating position. The delay switch 151 will also beopen.

As the engine coolant temperature reaches a temperature of between 120and 140 F., the temperature sensitive switch will open to deenergize thesolenoid coil 139. The blower motor 18 will then operate at a low blowpurge speed through the switch arm .140,

a conductor 152 and resistors 1R, 2R and 3R. This will purge the plenumof stored stale air.

As the recirculating door 56 closes and the fresh air door 59 opens, thedelay switch 151 will close and complete an energizing circuit throughthe switch arm 140 to the contact 81, through said delay switch 151.This will energize the blower motor 18 to drive the blower motor 18 at ahigh blower speed. As the passenger compartment warms up, the resistors3R, 2R and IR will be cut into the circuit under the control of theambient and in-car temperature sensing elements 20 and 22 respectively,the servo motor 11 and programmer operated thereby.

As the ambient temperature reaches a temperature of 40, The switch 153will close to energize the solenoid coil 154 to connect the compressor(not shown) to the engine, to be driven thereby.

The selector 12 will also connect the mode servo motor 40 to a source ofmodulated vacuum to move the mode door from heating to bi-level to airconditioning and provide a continuous modulation of discharge air fromfloor to bi-level to the instrument panel, in accordance with therequirements for heated or cooled air as determined by the sensor 10.

When cooling is required, the servo motor 11 moving the programmer inaccordance with modulated vacuum, determined by the sensor will energizethe contact 82 directly connected with contact A of the selector switch122 and will selectively cut the resistors 1R, 2R and 3R out of theblower motor circuit as the air blend door reaches the end of its travelin an air conditioning position. The overtravel spring 16 willaccommodate continued retractable movement of the servo motor 11 andplunger 13, and engage the contact finger 74 with the last contact 80 onthe contact plate 86. This will override the contacts R and M of themanual blower switch and directly connect the blower motor 18 to battery124, to drive the blower 18 at a high blower speed.

The contact fingers 77 will also engage the contact 83 and effectenergization of the water valve solenoid. This will shut off the flow ofhot .water through the heater coil. The contact finger 79 will alsoengage the contact 85, and energize the solenoid coil 139 and open thevalve 145 and the switch arm 140 of the relay 32. The servo motors 50and 51 will now be connected to source vacuum through the programmer l2and vacuum input 45 of the electro vacuum relay and close the fresh airdoor and place the recirculating door in its recirculating position andthe delay switch 151 will open. Air in the car will be recirculated bythe blower 18 driven at a high blower speed through the conductor 136,directly connected to the battery 124.

It should here be understood that during automatic heating and airconditioning the auto and clutch switches of the selector 122 areclosed. The deice vent switch is open.

When it is desired to turn the system to vent, the auto and vent deiceswitches are turned on while the clutch switch is turned off.

In order to deice, the auto, cluch and vent deice switches are turned onwhile when the selector 122 is in its defog position, the auto andclutch switches are on and the vent deice switch is turned off. In bothof these operations, the selector 12 is turned to defog and deicepositions to effect partial or full movement of the door 71.

It should further be understood that the selector 12 may override theautomatic program functions and change the operation of the aircirculating doors as required in accordance with the type ofconditioning or deicing or defoging operation that is required to beperformed.

I claim as my invention:

1. In an automotive vehicle automatic temperature control system of thetype including a heater core, an evaporator, a condenser, compressor anda clutch connecting the compressor to the engine of the automotivevehicle,

a source of vacuum,

a temperature sensor connected with said source of vacuum and sensingin-car and ambient air temperature and modulating source vacuum inaccordance with temperature requirements,

a vacuum selector having at least an automatic and a vent position,

a vacuum connection from said source of vacuum to said vacuum selector,

a vacuum connection from said sensor to said vacuum selector,

a power servo vacuum motor,

an air blend door operated thereby controlling the admission of heatedair, cooled air and blended heated and cooled air into the passengercompartment of the vehicle,

a vacuum connection from said sensor to said power servo vacuum motorconnecting said motor to modulated vacuum,

a blower,

a blower motor, operable to drive said blower to force heated and cooledair into the passenger compartment of the vehicle,

a programmer operated by said servo motor,

said programmer completing electrical connections to said blower motorfor varying the speed of said blower motor in accordance withtemperature requirements and the position of said vacuum power servo andsaid air blend door,

2. .The automatic temperature control system of claim 1,

wherein the energizing circuit to said blower motor includes,

a relay having normally closed contacts,

a solenoid coil operable to open said contacts,

an energizing circuit to said solenoid coil including a temperaturesensitive switch sensitive to engine temperature and closing when theengine is cold and energizing said solenoid coil to deenergize saidblower and hold said blower motor deenergized until opening of saidtemperature sensitive switch upon elevated engine coolant temperatureconditions.

3. The automatic temperature control system of claim 2, including twoservo motors connected in parallel,

a fresh air door operated by one of said motors,

a recirculting air door operated by the other of said motors alternatelyof operation of said fresh air door,

wherein the relay is an electro-vacuum relay,

wherein a vacuum connection is provided from source vacuum to said relayand another vacuum connection is provided from said relay to said twopower servo vacuum motors in parallel, for effecting closing of saidrecirculation door and opening of said fresh air door upon energizationof said solenoid coil.

4. The automatic temperature control system of claim 3, in which theparallel vacuum connection from said electro-vacuum relay to said vacuummotors includes,

a vacuum input having vacuum connection with said two motors,

a bleed passage bleeding vacuum connected with said vacuum input anddelaying closing of said recirculation door and opening of said freshair door for a predetermined time interval when the engine is cold, toaccommodate the purging of stored air prior to the circulation of freshair into the passen ger compartment of the vehicle.

5. The automatic temperature control system of claim 4, including aseries of resistors connected in series between said programmer and saidblower motor,

a time delay switch operated by said servo motor closing saidrecirculation door and closed upon closing of said door, to complete acircuit from said relay to said programmer,

and an electrical connection directly connecting said relay to saidblower motor through said resistors for energizing said blower motor ata low speed to purge the system for a predetermined time interval duringengine warm-up.

6. The automatic temperature control system of claim 5,

wherein the electro-vacuum relay includes a valve controlling thepassage of vacuum from said bleed orifice to the source of vacuum, and

wherein said valve is opened upon energization of said solenoid coil todelay closing of said recirculation door and opening of said fresh airdoor for a predetermined delayed time interval during engine warm-up.

7. The automatic temperature control system of claim 1, including,

a water valve controlling the passage of hot water to the heater corefor the vehicle,

electrical energizable means controlling the opening and closing of saidwater valve,

and an energizing circuit from said programmer to said electricalenergizable means energizable to connect said vacuum motor to a sourceof vacuum, to shut off said water valve and the supply of water to theheater core upon extreme travel of said first mentioned vacuum servomotor and programmer operated thereby where maximum cooling is required.

8. The automatic temperature control system of claim 7, including,

a vacuum motor for operating said water valve,

a connection from the source of vacuum to said vacuum motor,

and wherein the electrical energizable means includes a solenoidcontrolled valve connected in the energizing circuit from saidprogrammer and energized upon extreme travel of said servo vacuum motorand programmer for maximum cooling conditions.

9. The automatic temperature control system of claim 5,

wherein the time delay switch is carried by said servo motor closingsaid recirculation door,

wherein an operative connection is provided between said switch and saidservo motor for closing said switch upon closing of said recirculationdoor and opening of said fresh air door, to provide an energizingcircuit to said blower motor through said relay and said time delayswitch as the engine has warmed up.

10. The automatic temperature control system of claim 9, including anenergizing circuit to said blower through said relay and said resistorsfor bypassing said time delay switch upon closing of said relay, as saidrecirculation door remains closed and said time delay switch is open todrive the motor at a low blower speed and purge the system of storedair.

11. The automatic temperature control system of claim 10, including,

a water valve controlling the passage of water to the heater core forthe vehicle,

a connection from the source of vacuum to said water valve including avacuum control valve and a solenoid operable to open said valve,

an energizing circuit from said programmer to said solenoid forenergizing said solenoid and effecting opening of said vacuum controlvalve and closing of said water valve upon extreme travel of said servomotor and programmer into a maximum cooling position.

12. The automatic temperature control system of claim 1, including,

a second power servo vacuum motor, said vacuum selector beingpositionable to connect said second power servo vacuum motor to moduatedvacuum, modulated by said temperature sensor when in an automaticposition,

a mode door operated by said second power servo vacuum motor to providea continuous modulation of air discharged by said blower from floor tobilevel to panel and from heating to cooling.

13. The automatic temperature control system of claim 12, including,

two additional power servo vacuum motors connected in parallel,

a fresh air door operated by one of said additional power servo vacuummotors,

a recirculation door operated by the other of said additional powerservo vacuum motors alternately of operation of said fresh air door toclose as said fresh air door opens and vice versa,

an electro-vacuum relay,

a vacuum connection is from source vacuum to said relay and anothervacuum connection from said relay to said two additional power servovacuum motors,

said electro-vacuum relay including a solenoid coil and contactsnormally closed and opening upon energization of said solenoid coil,

an energizing circuit for said solenoid coil and including a temperaturesensitive switch sensitive to engine temperature and closed when theengine is cold, and energizing said solenoid coil to open its contactsand prevent energization of said blower motor, and holding said blowermotor deenergized until opening of said temperature switch upon elevatedengine coolant temperature conditions, energization of said solenoidcoil also opening said electro-vacuum relay valve, to connect said powerservo motors to source vacuum in parallel, to effect closing of saidrecirculating door and opening of said fresh air door as the coolanttemperature reaches a predetermined comfortable temperature level,

said temperature sensitive switch opening upon elevated engine coolanttemperatures to deenergize said solenoid coil and effect closing of saidrelay contacts and closing of said electro-vacuum relay valve andheating of the passenger compartment under control of said programmer.

14. The automatic temperature control system of claim 13, in which thevacuum connection from said electro-vacuum relay to said vacuum motorsconnected in parallel, includes,

a vacuum input for said electro-vacuum relay and a bleed passageway insaid input delaying closing of said recirculation door and opening ofsaid fresh air door for a predetermined time interval upon cold enginecoolant conditions.

15. In an automotive vehicle automatic temperature control system of thetype having a heater core, an evaporator, a condenser, a compressor, anda clutch connecting the compressor to the engine of the automotivevehicle,

a source of vacuum,

a blower,

a blower motor, operable to drive said blower to force heated and cooledair into the passenger compartment of the vehicle,

a programmer,

a plurality of resistors connected in series,

said programmer connecting said blower motor in an electrical energizingcircuit through said resistors, and cutting said resistors out of thecircuit, for varying the speed of said motor in accordance withtemperature requirements,

a relay having normally closed contacts,

a solenoid coil for opening said contacts when energized,

an energizing circuit to said solenoid coil including a temperaturesensitive switch sensitive to engine temperature and closing when theengine is cold and energizing said solenoid coil to deenergize saidblower and hold said blower motor deenergized until opening of saidtemperature sensitive switch upon elevated coolant temperatureconditions.

16. The automatic temperature control system of claim 15, including,

two servo motors connected in parallel,

a fresh air door operated by one of said motors,

a recirculating air door operated by the other of said motorsalternately of operation of said fresh air door,

wherein the relay is an electro-vacuum relay,

wherein a vacuum connection is provided from source vacuum to said relayand another vacuum connection is provided from said relay to said twopower servo vacuum motors in parallel, for effecting closing of saidrecirculation door and opening of said fresh air door upon energizationof said solenoid coil.

17. The automatic temperature control system of claim 16, in which theparallel vacuum connection from said electro-vacuum relay to said vacuummotors includes,

a vacuum input having vacuum connection with said two motors,

a bleed passage bleeding vacuum connected with said vacuum input anddelaying closing of said recirculation door and opening of said freshair door for a predetermined time interval when the engine is cold, toaccommodate the purging of stored air prior to the circulation of freshair into the passenger compartment of the vehicle.

18. The automatic temperature control system of claim 16, including,

a time delay switch operate by said servo motor closing saidrecirculation door and closed upon closing of said door, to complete acircuit from said relay to said programmer,

and an electrical connection directly connecting said relay to saidblower motor through said resistors for energizing said blower motor ata low speed to purge the system for a predetermined time interval duringengine warm-up.

1. In an automotive vehicle automatic temperature control system of thetype including a heater core, an evaporator, a condenser, compressor anda clutch connecting the compressor to the engine of the automotivevehicle, a source of vacuum, a temperature sensor connected with saidsource of vacuum and sensing in-car and ambient air temperature andmodulating source vacuum in accordance with temperature requirements, avacuum selector having at least an automatic and a vent position, avacuum connection from said source of vacuum to said vacuum selector, avacuum connection from said sensor to said vacuum selector, a powerservo vacuum motor, an air blend door operated thereby controlling theadmission of heated air, cooled air and blended heated and cooled airinto the passenger compartment of the vehicle, a vacuum connection fromsaid sensor to said power servo vacuum motor connecting said motor tomodulated vacuum, a blower, a blower motor, operable to drive saidblower to force heated and cooled air into the passenger compartment ofthe vehicle, a programmer operated by said servo motor, said programmercompleting electrical connections to said blower motor for varying thespeed of said blower motor in accordance with temperature requirementsand the position of said vacuum power servo and said air blend door, 2.The automatic temperature control system of claim 1, wherein theenergizing circuit to said blower motor includes, a relay havingnormally closed contacts, a solenoid coil operable to open saidcontacts, an energizing circuit to said solenoid coil including atemperature sensitive switch sensitive to engine temperature and closingwhen the engine is cold and energizing said solenoid coil to deenergizesaid blower and hold said blower motor deenergized until opening of saidtemperature sensitive switch upon elevated engine coolant temperatureconditions.
 3. The automatic temperature control system of claim 2,including two servo motors connected in parallel, a fresh air dooroperated by one of said motors, a recirculting air door operated by theother of said motors alternately of operation of said fresh air door,wherein the relay is an electro-vacuum relay, wherein a vacuumconnection is provided from source vacuum to said relay and anothervacuum connection is provided from said relay to said two power servovacuum motors in parallel, for effecting closing of said recirculationdoor and opening of said fresh air door upon energization of saidsolenoid coil.
 4. The automatic temperature control system of claim 3,in which the parallel vacuum connection from said electro-vacuum relayto said vacuum motors includes, a vacuum input having vacuum connectionwith said two motors, a bleed passage bleeding vacuum connected withsaid vacuum input and delaying closing of said recirculation door andopening of said fresh air door for a predetermined time interval whenthe engine is cold, to accommodate the purging of stored air prior tothe circulation of fresh air into the passenger compartment of thevehicle.
 5. The automatic temperature control system of claim 4,including a series of resistors connected in series between saidprogrammer and said blower motor, a time delay switch operated by saidservo motor closing said recirculation door and closed upon closing ofsaid door, to complete a circuit from said relay to said programmer, andan electrical connection directly connecting said relay to said blowermotor through said resistors for energizing said blower motor at a lowspeed to purge the system for a predetermined time interval duringengine warm-up.
 6. The automatic temperature control system of claim 5,wherein the electro-vacuum relay includes a valve controlling thepassage of vacuum from said bleed orifice to the source of vacuum, andwherein Said valve is opened upon energization of said solenoid coil todelay closing of said recirculation door and opening of said fresh airdoor for a predetermined delayed time interval during engine warm-up. 7.The automatic temperature control system of claim 1, including, a watervalve controlling the passage of hot water to the heater core for thevehicle, electrical energizable means controlling the opening andclosing of said water valve, and an energizing circuit from saidprogrammer to said electrical energizable means energizable to connectsaid vacuum motor to a source of vacuum, to shut off said water valveand the supply of water to the heater core upon extreme travel of saidfirst mentioned vacuum servo motor and programmer operated thereby wheremaximum cooling is required.
 8. The automatic temperature control systemof claim 7, including, a vacuum motor for operating said water valve, aconnection from the source of vacuum to said vacuum motor, and whereinthe electrical energizable means includes a solenoid controlled valveconnected in the energizing circuit from said programmer and energizedupon extreme travel of said servo vacuum motor and programmer formaximum cooling conditions.
 9. The automatic temperature control systemof claim 5, wherein the time delay switch is carried by said servo motorclosing said recirculation door, wherein an operative connection isprovided between said switch and said servo motor for closing saidswitch upon closing of said recirculation door and opening of said freshair door, to provide an energizing circuit to said blower motor throughsaid relay and said time delay switch as the engine has warmed up. 10.The automatic temperature control system of claim 9, including anenergizing circuit to said blower through said relay and said resistorsfor bypassing said time delay switch upon closing of said relay, as saidrecirculation door remains closed and said time delay switch is open todrive the motor at a low blower speed and purge the system of storedair.
 11. The automatic temperature control system of claim 10,including, a water valve controlling the passage of water to the heatercore for the vehicle, a connection from the source of vacuum to saidwater valve including a vacuum control valve and a solenoid operable toopen said valve, an energizing circuit from said programmer to saidsolenoid for energizing said solenoid and effecting opening of saidvacuum control valve and closing of said water valve upon extreme travelof said servo motor and programmer into a maximum cooling position. 12.The automatic temperature control system of claim 1, including, a secondpower servo vacuum motor, said vacuum selector being positionable toconnect said second power servo vacuum motor to modu ated vacuum,modulated by said temperature sensor when in an automatic position, amode door operated by said second power servo vacuum motor to provide acontinuous modulation of air discharged by said blower from floor tobi-level to panel and from heating to cooling.
 13. The automatictemperature control system of claim 12, including, two additional powerservo vacuum motors connected in parallel, a fresh air door operated byone of said additional power servo vacuum motors, a recirculation dooroperated by the other of said additional power servo vacuum motorsalternately of operation of said fresh air door to close as said freshair door opens and vice versa, an electro-vacuum relay, a vacuumconnection is from source vacuum to said relay and another vacuumconnection from said relay to said two additional power servo vacuummotors, said electro-vacuum relay including a solenoid coil and contactsnormally closed and opening upon energization of said solenoid coil, anenergizing circuit for said solenoid coil and including a temperaturesensitive switch sensitive to engine temperature and closed when theengine is colD, and energizing said solenoid coil to open its contactsand prevent energization of said blower motor, and holding said blowermotor deenergized until opening of said temperature switch upon elevatedengine coolant temperature conditions, energization of said solenoidcoil also opening said electro-vacuum relay valve, to connect said powerservo motors to source vacuum in parallel, to effect closing of saidrecirculating door and opening of said fresh air door as the coolanttemperature reaches a predetermined comfortable temperature level, saidtemperature sensitive switch opening upon elevated engine coolanttemperatures to deenergize said solenoid coil and effect closing of saidrelay contacts and closing of said electro-vacuum relay valve andheating of the passenger compartment under control of said programmer.14. The automatic temperature control system of claim 13, in which thevacuum connection from said electro-vacuum relay to said vacuum motorsconnected in parallel, includes, a vacuum input for said electro-vacuumrelay and a bleed passageway in said input delaying closing of saidrecirculation door and opening of said fresh air door for apredetermined time interval upon cold engine coolant conditions.
 15. Inan automotive vehicle automatic temperature control system of the typehaving a heater core, an evaporator, a condenser, a compressor, and aclutch connecting the compressor to the engine of the automotivevehicle, a source of vacuum, a blower, a blower motor, operable to drivesaid blower to force heated and cooled air into the passengercompartment of the vehicle, a programmer, a plurality of resistorsconnected in series, said programmer connecting said blower motor in anelectrical energizing circuit through said resistors, and cutting saidresistors out of the circuit, for varying the speed of said motor inaccordance with temperature requirements, a relay having normally closedcontacts, a solenoid coil for opening said contacts when energized, anenergizing circuit to said solenoid coil including a temperaturesensitive switch sensitive to engine temperature and closing when theengine is cold and energizing said solenoid coil to deenergize saidblower and hold said blower motor deenergized until opening of saidtemperature sensitive switch upon elevated coolant temperatureconditions.
 16. The automatic temperature control system of claim 15,including, two servo motors connected in parallel, a fresh air dooroperated by one of said motors, a recirculating air door operated by theother of said motors alternately of operation of said fresh air door,wherein the relay is an electro-vacuum relay, wherein a vacuumconnection is provided from source vacuum to said relay and anothervacuum connection is provided from said relay to said two power servovacuum motors in parallel, for effecting closing of said recirculationdoor and opening of said fresh air door upon energization of saidsolenoid coil.
 17. The automatic temperature control system of claim 16,in which the parallel vacuum connection from said electro-vacuum relayto said vacuum motors includes, a vacuum input having vacuum connectionwith said two motors, a bleed passage bleeding vacuum connected withsaid vacuum input and delaying closing of said recirculation door andopening of said fresh air door for a predetermined time interval whenthe engine is cold, to accommodate the purging of stored air prior tothe circulation of fresh air into the passenger compartment of thevehicle.
 18. The automatic temperature control system of claim 16,including, a time delay switch operate by said servo motor closing saidrecirculation door and closed upon closing of said door, to complete acircuit from said relay to said programmer, and an electrical connectiondirectly connecting said relay to said blower motor through saidresistors for energizing said blower motor at a low speed to purge thesystem for a predetermined time interval during engine warm-up.